sea anemones

Sea anemones are a group of water-dwelling, predatory animals of the order Actiniaria. There are more than 1,000 species of sea anemones found throughout the world’s oceans, many attached to rocks on the seafloor. Their bodies are composed of an adhesive pedal disk, a cylindrical body, and an array of tentacles. The tentacles are triggered by the slightest touch, firing a harpoon-like filament into their victim and injecting a paralyzing neurotoxin. 

Estefanía Rodríguez, Associate Curator of Invertebrate Zoology at the American Museum of Natural History is studying the fascinating varieties of anemones and other sea life in Antarctica. In 2014, Dr. Rodríguez discovered a giant anemone-like creature with tentacles reaching more than 6.5 feet long that actually belongs to an entirely new order of animals, demonstrating there is still much to be learned about polar marine life!

See anemones, penguins, and seals in Beneath the Ice, and immersive dome installation now on view in the Milstein Hall of Ocean Life, running through May 27.  

Image: Actiniae Seeanemonen from Ernst Haeckel’s Kunstformen der Natur

A painting of diverse sea anemones by Giacomo Merculiano, 1893.

These cnidarians are predators feeding mainly on fishes and crustaceans. They have nematocysts containing very toxic actinotoxins that they shoot into prey with hair-like structures. These animals have a fossil record dating to the middle Cambrian (more than 500 million years ago), though having soft-tissue bodies, fossilization is rare. Also see this video with a live anemone being pursued by its own predator.

Striped shore crab (Pachygrapsus crassipes) and unidentified sea anemones, at Torrey Pines State Beach, San Diego, California. 

This stout fellow was sheltering in a crevice in the rock, in a gap barely big enough to insert the camera lens. All of the creatures involved in making this photo were soaked through before it was done. 

Please click photo for a full view.